Contract 3

Ethereum / Quorum compatible library that makes smart contract compilation, deployment and interaction easy (both standard and as signed transactions)

Installation

Go to the project directory and type

npm install --save contract3

Requirements

Tested with Node 8.0+ and web3 version 1.2.6

Examples

Below are example of using this library to interact with Smart Contracts

Standard Smart Contract Interaction

    const Web3 = require('web3');
    const web3 = new Web3(new Web3.providers.HttpProvider('http://localhost:8545'));
    const Contract3 = require('contract3');
    let contract3 = new Contract3(web3);
    contract3.setSolc(require('solc'));
 
    async function deploy(){
        let Administered = 'contract Administered { .. }';
        let Asset = 'contract Asset { .. }';
        let input = {
            'Administered.sol': {
                content: Administered
            },
            'Asset.sol': {
                content: Asset
            }
        }
 
        const defaultAccount = await web3.eth.getCoinbase();
        const contractInstances = await contract3.getInstances(input);
        //Getting instance of the contract, by Contract name
        const AssetInstance = contractInstances['Asset']();
 
        try{
 
            const ContractDeploymentResponse = await AssetInstance.deployContract(
                //args to constuctor
                ["computerSystem",defaultAccount,100],
                //Options
                {
                    gas:4712388
                });
                console.log('Contract Address:',ContractDeploymentResponse.options.address)
                const result = await AssetInstance.get('getValue',[]);
                console.log('Value of Asset:', result)
                console.log('Changing Asset Value')
                const result2 = await AssetInstance.set('changeValue', [134],{gas:40000});
                if (result2) {
                    const result = await AssetInstance.get('getValue',[]);
                    console.log('New Asset Value:', result)
                }
        } catch(e){
            console.log(e)
        }
    }
    deploy();

Interacting with Smart Contract as Singed Transaction

This method is useful for consuming apis of services like infura to interact with ethereum blockchain

    const Web3 = require('web3');
    const web3 = new Web3(new Web3.providers.HttpProvider('http://localhost:8545'));
    const Contract3 = require('contract3');
    let contract3 = new Contract3(web3, "0x4E5feB13de0e29BC4aeA01........"/*Ethereum_Address*/, "dfae4457ef0fd39416597da2fab6739..........."/*Private_Key*/, true/*Automatically fetch current nonce flag*/, {chain: 'ropstein'});
    const abi ={..};
    const contractInstance = await contract3.getInstance(abi);
    //Deploying contrcat
    contractInstance.signedTxDeployContract(["arg1",true],
        {
            gas: 4712388,
            value: '0x00'
        })
 
    //Calling a contract function 
    const data = await instance.signedTxFunctionCall('storeSellerInvoice', ["0xfa3a43c04170d3b35bae1a8d8e7c83bc5add4ed8a36f7e0586814344d1bef229"],
        {
            gas: 4712388,
            value: '0x00'
        });

For calling contract methods as signed tx refer to "Contract Instance methods" section

Class functions

constructor(web3, address, privateKey, nonceFetchFlag, chainConfig)

Constructor takes web3 object as argument.

1. web3 a intialized web3 instance
2. address is the ethereum account address
3. privateKey is the private key to be used for signing transaction.
4. nonceFetchKey is an optional flag to automatically fetch latest transaction count of the account
5. chainConfig is chainConfig chain config for etherumjs-tx module => eg. { chain: 'mainnet', hardfork: 'petersburg' } . Only required if signed transactions are used account

/*Pre Requisite*/
const Web3 = require('web3');
const provider = new Web3.providers.HttpProvider(YOUR_URL);
const web3 = new Web3(provider);
/*Pre-requistie End*/
//For signed
const contract3 = new Contract3(web3, "0xe3424234...","4de223424324324....", true);
//For non-singed tx
const contract3 = new Contract3(web3, "0xe3424234...");

setSolc(solc)

Constructor takes web3 object as argument.

1. solc is Solc instance if compiling is needed

const solc = require('solc');
...
contract3.setSolc(solc);

compile(source)

Compiles and returns bytes code and other details as produced by solc

1. source is JSON object with Contract file name as key and Contract content as value

    let Administered = 'contract Administered { .. }';
    let Asset = 'contract Asset { .. }';
    let input = {
        'Administered.sol': {
            content: Administered},
        'Asset.sol': {contenet: Asset}
    }
    contract3.compile(input)

deploy(abi, code, args, options)

Deploys a existing compiled smart contract. Returns promise containing the instance, the receipt and transaction hash of deployed smart contract

1. abi is the ABI of the smart contract
2. code is the bytecode of the smart contract
3. args are the constuctor arguments for initializing the contract
4. options contains standard web3 options like gas, value, etc.

    contract3.deploy([...], '0x45..', ['1'], {
        gas:4712388,
        //privateFor: [], /*This is for Quorum*/
        //value:<Any Ether to send>
    })

getInstances(source)

Compiles and returns instances of the the contracts

1. source is JSON object with Contract file name as key and Contract content as value

    let Administered = 'contract Administered { .. }';
    let Asset = 'contract Asset { .. }';
    let input = {
        'Administered.sol': Administered,
        'Asset.sol': Asset
    }
    const contractInstances = await contract3.getInstances(input);
    //Getting a contract instance by name of the smart contract
    const Asset = contractInstances['Asset'];

getInstance(abi,address)

Use this method to get instance of pre-compiled smart contract (Does not work if you want to deploy smart contract)

1. abi is the ABI of the smart contract
2. address is the ethereum smart contract address

    const abi ={..};
    const address='0xad12313...';
    const contractInstance = await contract3.getInstance(abi,address);
 

Contract Instance methods

deployContract(args, options, isTxHashOnly)

Deploys the contract as a singed transaction. Deploys the contract and creates an instances using args passed as array.

1. args are arguments to be passed to constructor
2. options contains standard web3 options like gas, value, etc.
3. isTxHashOnly Optional Flag to resolve once txHash is available instead of waiting till transaction is confirmed and receipts available

Returns transaction reciept if isTxHashOnly is false or undefined else gives back transaction hash

    let Administered = 'contract Administered { .. }';
    let Asset = 'contract Asset { .. }';
    let input = {
        'Administered.sol': Administered,
        'Asset.sol': Asset
    }
    const contractInstances = await contract3.getInstances(input);
    const AssetInstance = contractInstances['Asset'];
    try{
        const ContractObject = await AssetInstance.deployContract(
            //args to constuctor
            ["computerSystem",defaultAccount,100],
            //Other Parameters
            {
                value: 0,
                gas:4712388
            });
        console.log('Contract Address: ',ContractObject.options.address)
    }
    catch (err) {
        console.log(err)
    }

deployContractEncoded(args)

Interface to get encoded transaction data for contact deployment

1. args are arguments to be passed to constructor

    const abi ={..};
    const contractInstance = await contract3.getInstance(abi);
    console.log(contractInstance.deployContractEncoded([]));

signedTxDeployContract(args, options, isTxHashOnly)

Deploys the contract as a singed transaction.

1. args are arguments to be passed to constructor
2. options contains standard web3 options like gas, value, etc.
3. isTxHashOnly Optional Flag to resolve once txHash is available instead of waiting till transaction is confirmed and receipts available

Returns transaction reciept if isTxHashOnly is false or undefined else gives back transaction hash

    const abi ={..};
    const contractInstance = await contract3.getInstance(abi);
    const txData = await contractInstance.signedTxDeployContract(["arg1",true],
        {
            gas: 4712388,
            value: '0x00'
        });

setAddress(address)

A setter function that sets the address of the instance to call functions of an already deployed contracts

1. address Etherum address of the deployed contract

    const AssetInstance = contractInstances['Asset'];
    AssetInstance.setAddress('0x234924...');

get(functionName,args)

A getter function that issue a call to function represented by functionName by passing the arguments given in array format.

1. functionName Smart contract function name
2. args are arguments to be passed to constructor. Its a array so multiple arguments can be passed dynamically

    const result = await AssetInstance.get('getValue',[]);
    console.log(result)

set(functionName,args,options, isTxHashOnly)

Set is used to perform send transactions on functions of a deployed smart contract.

1. functionName Smart contract function name
2. args are arguments to be passed to constructor. Its a array so multiple arguments can be passed dynamically
3. options contains standard web3 options like gas, value, etc.
4. isTxHashOnly Optional Flag to resolve once txHash is available instead of waiting till transaction is confirmed and receipts available

Returns transaction reciept if isTxHashOnly is false or undefined else gives back transaction hash

    const result2 = await contracts.set(ContractObject,'set', [134],{gas: 100000});
    if (result2) {
        const result = await contracts.get(ContractObject,'get',[]);
        console.log(result)
    }

signedTxFunctionCall(functionName, args, options, isTxHashOnly)

Deploys the contract as a singed transaction.

1. functionName Smart contract function name
2. args are arguments to be passed to constructor
3. options contains standard web3 options like gas, value, etc.
4. isTxHashOnly Optional Flag to resolve once txHash is available instead of waiting till transaction is confirmed and receipts available

Returns transaction reciept if isTxHashOnly is false or undefined else gives back transaction hash

    const abi ={..};
    const contractInstance = await contract3.getInstance(abi);
    const data = await contractInstance.signedTxFunctionCall('storeSellerInvoice', ["0xfa3a43c04170d3b35bae1a8d8e7c83bc5add4ed8a36f7e0586814344d1bef229"],
        {
            gas: 4712388,
            value: '0x00'
        });

getFunctionEncoded(functionName, args)

Returns encoded value for a function to use for sending signed transaction

1. functionName Smart contract function name
2. args are arguments to be passed to constructor

    const abi ={..};
    const contractInstance = await contract3.getInstance(abi);
    console.log(contractInstance.getFunctionEncoded("get",[]));

getTranactionReceipt()

Returns transaction receipt assosciated with contract deployment

getCode()

Returns bytecode of the contract

getInstance()

Returns web3 contract instance of the instance

getReceipt(hash)

1. hash Transaction Hash

Returns receipt with decoded transaction log

getReceipt(hash)

1. hash Transaction Hash

Returns receipt with decoded transaction log

getTransaction(hash)

1. hash Transaction Hash

Returns transaction data with decoded input